1. Field of the Invention
The present invention pertains to apparatus for controlling emissions from internal combustion engines. More specifically, the present invention pertains to emission control apparatus particularly suitable for diesel fueled engines for removal of particulates therefrom. Specifically, the present invention pertains to emission control apparatus, primarily for removing particulates from the exhaust of a diesel engine but also for reduction of noise and/or noxious gases emitted therefrom.
2. Brief Description of the Prior Art
Noise reduction apparatus for internal combustion engines has existed for many years. Sometimes called silencers or mufflers, such noise reduction apparatus typically includes a housing the inlet of which is connected to the exhaust of an internal combustion engine and in which is provided various types of baffles or other silencing components for reduction of the noise produced at the exhaust of the internal combustion engine.
In more recent years, emission control apparatus has included, in addition to noise reduction components, components for reducing unwanted emissions from the exhaust of an internal combustion engine, e.g. noxious components such as nitrogen oxide, carbon monoxide and other unburned hydrocarbons. Increased regulation by state and federal authorities have demanded continued improvement in this area.
One of the most effective means for reducing noxious emissions from engine exhaust appears to be the utilization of some type of catalyst to convert the noxious gasses to water, nitrogen, carbon dioxide and other less noxious compounds. Emission control apparatus, manufactured in recent years, in which the functions of noise reduction and noxious gas reduction are combined in a single device or apparatus may be seen in U.S. Pat. Nos. 4,209,493; 4,601,168 and 5,016,438.
The burning of diesel fuel in diesel engines or diesel/gas engines results in exhaust in which, in addition to noxious gases such as nitrogen oxide, carbon monoxide and other unburned hydrocarbons, there are substantial amounts of smoke and/or particulates. While the combination emission control apparatus for reduction of noise and noxious gases, such as those previously mentioned herein, may be effective in reducing noise and noxious gases emitted with the exhaust of the diesel engine, they may not be effective in removing or reducing particulates therefrom. Furthermore, the particulates in the exhaust of a diesel engine may reduce the effectiveness of noise reduction and noxious gas reduction components of emission control apparatus by coating various surfaces thereof, i.e. catalytic cells for reduction of noxious gases. Since there is continued need and regulatory pressure for reduction of particulates in the exhaust of diesel engines, improved emission control apparatus for such purposes is desired.